Mudryk touched down with the squad in Hong Kong on Monday, his return cleared once the anti-doping case against him was resolved, and after two training sessions Alonso judged him ready to feature in the 1-0 defeat, sent on for the final stretch in place of Nicolas Jackson, who had himself come on at half-time.
"I'm really pleased for him," Alonso said afterwards. "It was emotional for everyone from the club to see him back.
"When I told him before the game he could play 10 or 15 minutes, he was thrilled for sure. It was after such a long period that he couldn't play with the team, so it was a great feeling for him and for everyone else."
The manager added that the decision went beyond team selection.
"It was more than a football decision. It was a human decision and emotional decision to give him this boost, to feel the great support that he got and the great reception when he came on the pitch."
Levi Colwill and Cole Palmer were both missing from the squad, though Alonso played down any concern, pointing instead to the club's cautious approach during the tour.
"They had some discomfort; Cole with a contact injury and Levi as well," he said. "It's not a big thing, but we want to be cautious because there's no point in risking anything. So, we'll go step by step, day by day."
The other story to emerge from Hong Kong was the performance of 16-year-old academy product Mahdi Nicoll-Jazuli, who started in midfield alongside captain Moises Caicedo against a Juventus pairing of Manuel Locatelli and Douglas Luiz, and held his own before making way for Romeo Lavia after roughly an hour.
"It's incredible – I don't even remember when I was 16 who I was playing against," Alonso said. "But he was playing against Locatelli, against Douglas Luiz, these experienced players.
"For sure it's something that he will remember in the future. You can learn so much, as what it takes to be a top-level player is not just about having good technique.
"It's about understanding the game, having composure with the ball, when to defend hard, many things that he still has to learn. This is what I like: to see players progress. So far, they have this desire to learn."
Reflecting on the game itself – Chelsea's third of a tour taking in Australia and Asia, and their second successive defeat after also losing to Tottenham Hotspur – Alonso pointed to a strong start undone by a lapse before half-time.
"We started pretty well; the first 30-to-35 minutes we played with good control and created a few chances," he said. "In the last minutes of the half, a little bit like on Saturday, we lost a little bit of the control.
"In the second half, there were many changes and the game was not that controlled, a little bit unstable with all the substitutions. Unfortunately, we didn't get to win, but it's a process, minutes for everyone, and we have two more games before we go back to London."